Carburetor



INVENTOR,

und-v ATTORNEYS.

lN. A. cHRls-rENsEN nl um* 1. 1924 Patented Feb. 5, 1929.

UNITED `.STATES NIELS AQ CHRIsTENsEN, oF MILWAUKEE, WISCONSIN.

CARBURETOB.

appncauonmea March 1, 1924. serial No. 696,199.

The invention relates to earburetors, and

more particularly those operating under pressure.

rlhe object ofthe invention is to provide a pressure-feed carburetor for starting systems for internalcombustion engines ol the type shown in my prior United States Letters Patents No, 1,185,874 of J une 16, 1916, and No. 1,253,669 of January 15, 1918, and in. my application Serial No. 453,798, filed hilarch 19, 1921, said application Serial No. 453,798 having since the tiling of this application issued as United States Letters Patent No, 1,517,533, on December 2, 1924.

The invention further consists in the several features hereinafter forth and more particularly delined by claims at the conclusion hereof.

ln the drawings: Fig. 1 is a vertical sectional View taken on the line 1-1 of Fig. 3; Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1; Fig. 3 is a plan vieu1 of the carburetor embodying the invention.

This carburetor is preferably now made as an individual unit, separate from the starter or compressor unit,` and except for the valves, their `seats and operating means and the nozzle, is 4of a single casting forming a casing designated generally by the numeral 4.

The casing has a lioat chamber 5, a fuel chamber or reservoir 6, an air passage 7 for compressed air, and a mixing passage 8 for compressed air and fuel formed therein.

The float chamber 5 has a. 'float 9 Working therein and controlling a needle valve 10 which controls the passage of fuel through a duct 11 in an inlet plug 12. This plug 12 has a threaded connection 14 with the float chamber top 13, removably secured to the casting. Liquid fuel led from any suitable source through suitable piping to the tapped inlet 15 above the plug. A baille cap 16 lits over the upper end of the plug and provides restricted commuuications 17 opening downwardly and' registering with grooves 1S formed un the tup of the plug 12 and communicating with the inlet to the duct 11 whereby foreign matter and impurities are prevented from passing to said duct. lmpuritics deposited in the annular space ,be lou' the cap 16 may be removed from time to time by remo 'ing the top 13 and taking out the plug or cage 12. The needle valve is limited in its upper movement by contact With its seat 19 and in its lower movement Communication between the float `cham-` ber 5 and the reservoir `6 is through a passage 23 in a' screw-plug 24, said passage bef ing controlled by a check valve 25 closingr toward said float chamber and in the form of a bolthaving its head adapted to seat against the flat seat 25 of the plug 24," and its nutI 26 serving as a stop to limit its movement but not preventing passage of fuel through said passage 23.

The air passage 7 has an upper horizontally disposed portion 26, a vertical portion 27 and a lower portion 28 adjacent the inlet end of the mixing passage 8.

` A passage 29, threaded at its upper end, is provided between the fuel chamber 6 and the passage 7, and a removable fuel nozzle 3() has a threaded portion engaging the tlneadedportion of said passage.` At its upper end this nozzle projects into the mixing passage and at its lower end said nozzle is provided with spaced slots 31 for engagement with a screw-driver or other suitable tool for the purpose of installation or re moval, an assembly opening 32 being provided in the bottom and closed by a screwplug 33.

y A11 opening 34 provides a communication between the passage 7 and the chamber 6, to equalize the air pressure at the inlet to the passage 7 and the space above the fuel. The air pressure on the fuel in chamber (S is slightly greater than that of the air in pas- 7 adjacent the nozzle and this causes a feeding effect of the fuel at the nozzle.

For starting, the `float permits of filling the chamber 6, as Well as the lower end of passages 7 and 8, with liquid fuel, such as gasoline or other suitable fuel, up to a level ,indicated by the dotted line 35, which is more than sufficient for one operation of the starter,`

lVith this construction,` when compressed air is allowed to flow through the inlet 3G to the passage 7, its first effect is to pick up the fuel which has overflowed through the nozzle into the lower end of the mixing tube, the part 28 and the lower part 27 of the passage 7, Which parts form a temporary l fuel reservoir, and carry this fuel along with it to a distributor, not shown, from which the mixture thus formed passes to the cylinders of the engine and after taking up the fuel in this temporary reservoir the Continued flow of air through the passage 7 to the passage 8 draws the fuel out of the nozzle 30 and mixes this fuel with air in the passage 8. The check valve 25 prevents any back flow of fuel or air into the float chamber when the Compressed air is on.A

The construction above described has the advantage oi' being simple and free from complicated operating parts, and is well adapted for the purpose described.

What I Claim as my invention is:

l. In a carburetor, the Combination of a casing having` a float chamber, a fuel reservoir, a Compressed air passage and a mixing passage formed therein, a eheCk-valveeow trolled passage between said float chamber and reservoir, and a nozzle extending from said reservoir through a part of said air passage into said mixing' passage, said air passage having equalizing communica-tion with the space above the t'uel in said reser voir.

2. In a Carburetor, the Combination of a Casing having a fuel reservoir, a mixing passage and a compressed air passage extending along the top of said reservoir and down to a space below the inlet to said mixing passage, said air passage having an opening in its upper portion into the upper part o'l' said reservoir, a nozzle extending 'trom said reservoir through said space below the inlet and int-o said mixing passage, and means for permitting initial filling said reservoir to a height above said nozzle wherein7 a temporary reservoir of fuel is iormed in the lower parts of said air and mixing passages.

In testimony whereof I atiix my signature.

NIELS A. CHRISTENSEN 

